EwE Training-Workshop

GEF/LME Regional Training-Workshop on the Use of Ecopath with Ecosim (EwE) for Ecosystem-Based Management of Fisheries

The GEF/LME Regional Training Workshop on the Use of Ecopath with Ecosim for Ecosystem-based Management of Fisheries was held January 31 to February 5, 2008 at the M.S. Swaminathan Hall of the International Rice Research Institute (IRRI), Los Baños, Laguna. This workshop was initiated by the Fisheries Centre of University of British Columbia (UBC) and was hosted at The WorldFish Center – Philippine Office.

The workshop was opened by the IRRI Director General, Dr. Robert Ziegler, who was pleased with the EwE software which reminded him of his experience in plant ecosystem management. He expressed his appreciation in choosing IRRI as the venue for the workshop since one of the goals of IRRI was to provide support to projects facilitated by other CGIAR centers.

In his welcome statement, Dr. Villy Christensen expressed his excitement as this is the first time that the new version of EwE is used in a training workshop after 2 years in the making. He added that this version incorporates database generated ecosystem models, e.g., FishBase and SeaLifeBase.

Elaborating further on use of databases for ecosystem modeling, Dr. Nicolas Bailly (Officer-In-Charge of WorldFish - Philippine Office) emphasized that there is a need to look not just in the biology but also in the socio-economic aspects of an organism. He added that through databases, like FishBase and SeaLifeBase, easy access to massive amount of heterogeneous data, turns information to knowledge.

A total of 31 participants from various institutions in China (Yellow Sea Fisheries Research Institute and South China Sea Fisheries Institute), Brunei (Department of Fisheries, Brunei), the Philippines (Bicol University, University of the Philippines and Bureau of Fisheries and Aquatic Resources) and from international organizations (Conservation International and The WorldFish Center- Philippine Office staff) (see Annex I). The training consisted of lectures and exercises that were undertaken over a period of 5 days (see Annex II).

The workshop had two components: application of EwE 6.0 to large marine ecosystems and .NET programming for user-defined modules. The application of EwE 6.0 permitted testing for bugs, calculation errors and message alerts. The programming component introduced the concept of modifying EwE 6.0 by adding user-defined plug-ins that would treat specific issues of a particular ecosystem.

Most participants were users of EwE 5.0 and expected a reorientation to EwE 6.0 and its differences from older versions. Some participants were new to the EwE software and wanted to apply EwE to bridge habitat changes with trophic dynamics and fishery and ecosystem management, e.g., by increasing harvestable biomass to 10% of total biomass. Others were looking forward to its application in terms of evaluation, i.e., how information generated can be used in policy-making. Participants working on databases were curious as to how data encoded in their database will be used in generating models thru the software.

During the lectures on Ecopath, Dr. Christensen put emphasis on using simple models instead of complex ones. He also said that there is no such thing as a perfect model (unless the model is the actual system). EwE models fit historical data that lead to plausible predictions for ecosystem management. Yes, data is needed. However, EwE analyses do not require extensive data. The crucial point is targeting specific questions and how likely/uncertain the models can answer these questions, thus, finding the gaps. Data with time series (30 - 40 years) and diet composition studies are important for analysis, comparison and predicting trends.

FishBase and SeaLifeBase were presented by Dr. Nicolas Bailly and Dr. Maria Lourdes Palomares. In Dr. Bailly's presentation, he mentioned that one of the barriers in developing regional ecosystem models is a country’s (un)willingness to share their data. Dr. Palomares added that although conscious effort was made in obtaining diet composition publications, diet information is scarce especially for non-fish organisms. She also presented some tools in FishBase, which can be used for generating information useful in making models through EwE.

Dr. Christensen said that a lot of time and effort was spent to translate EwE 5.0 to EwE 6.0. He added that this new version uses a different and simple interface for easy comprehension and communication, e.g., from scientists to politicians. Dr. Christensen encouraged the participants to publish and share their models. However, he stressed that since EwE users are at a steady increase, its proper use and analysis of data are called for.

During the Ecosim discussions, most questions referred to data encoding problems and interpreting of results. One of the main concerns was the length of time series data that would validate a prediction. Dr. Christensen specified that historical data can be sparse (2 points in time) as long as originating from observations. A slight confusion was caused by a bug that forced the software down. Overall, Ecosim impressed on the participants its potential power of predicting the behavior of ecosystem to changes and their management implications.

Participants were introduced to Ecospace, i.e., spatial applications of ecosystem models and their potential use in marine protected areas. The participants’ feedback was that this module is the most effective of the EwE software to communicate the behavior of ecosystems to exogenous factors because of the graphical representation of biomass changes given a set of factors on the ecosystem components, e.g., fishing pressure.

Some interesting notes mentioned during the workshop were:

  1. Future availability of spatial primary productivity information by LME linked to Ecospace through the SAUP server;
  2. Optimization routine in Ecospace (Ecoseed) - designate a number of cells as seed cells for potential MPAs;
  3. EwE network analysis plug-ins, e.g., contaminant tracing (PCB accumulation in an ecosystem);
  4. EwE software will be available in other languages.

In his closing statement, Dr. Christensen wrapped up the workshop by stressing the need for availability of more data and the importance of knowing the proper use of EwE. He said that he will be looking forward to new models using the new and improved version of EwE, which will be available via the web and the use of global databases, e.g., FishBase and SeaLifeBase, in building ecosystem models.

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